Former-head



FORMER HEAD Filed Feb. 29, 1952 1 1 Z wz 7 y 1 9 M 1 M a Z 2 4 3 Z J 5 0% M 7' H 7 a to Patented Oct. 30, 1934 Artur mm UNI STATES to Pacific Clay Products, Los Angeles, Caliii, a corporatioirof California Application February 29, 1932, Serial No. 595,795

Claims.

- This invention relates to clay working machinery and particularly to apparatus for pressing socket-end sewer pipe.

A broad object of the invention is to facilitate 5 the removal of the former-head, or socket core,

froma newly pressed socket on a large-size clay pipe, and to reduce the number of imperfect sockets formed on such pipe. As is well known, clay pipe of large size for use in sewers and similar purposes, is made by extruding moist and plastic clay between a pair of concentric dies spaced apart the thickness of the walls of the pipe to be formed. 'Such pipe is usually made with a socket or bell end to facilitate making connections between adjacent lengths of pipe. Such a socket is formed on the end of apipe by securing a former-head to the die press, this former head constituting, with the dies, 3. closed mold of proper configuration for shaping a'p'ipe socket, and forcing clay into the mold. After the socket is formed, the formerhead is removed to permit extrusion of the pipe from the die, the removal of the former-head being accomplished by first rotating it and then withdrawing it from contact with the newly formed clay socket.

Heretofore, difficulty has sometimes been encountered during removal of the former-head in N that the clay adhered in places to the head and 30 came away with it, thus ruining the socket.

In accordance with the present invention, damage from this cause is reduced by making the "former-headlin two sections movable relative to each other so that one section can be broken away from the newly formed clay socket while the other section supports the socket and prevents rupture thereof; thereafter the other section can readily be removed without damage to the socket because of its reduced area.

A' complete understanding of the invention can best be had from the following detailed description with reference to the accompanying drawing, in which: V

Figure 1 is an elevational sectional view of my on a clay press;

Figure 2 is a plan view of the former-head itself;

Figure '3 is a detail'v'iew showing the shape of 3 slots in a portion of thef ormer-h'ead; and

improved former-head as it appears in position orally at 2. The external die 2 is provided with a flange 3 at its upper end which seals against a flange 4 on the clay press 1 and is secured thereto by bolts 5. Secured in position within the external die 2 is a core 6, the lower portion 0 of which cooperates with an inwardly extended portion '7 of the external die 2 to provide an annular space of the dimensions of the pipe to be formed. The core 6 is maintained rigidly in a position central with respect to the external die 2 by a support 8 which extends up through the clay press cylinder 1, and is secured thereto by spiders, one of which is shown at 9,, these spiders comprising arms extending radially from the support 8 out to the walls of the cylinder 1 715 to permit the downward passage of clay through the cylinder 1. Any desired means may be employed to supply clay under pressure to the cylinder 1, and since such means is old and well known, it has not been shown in the drawing.

To provide an external form for producing a. socket on the lower end of the pipethe external die 2 is provided with an outwardly and down-'- wardiy extending skirt '10, the inner surface of which skirt is shaped to correspond with the 00 outer surface of the pipe socket to be produced. To shape or form the inner surface of the socket, a former-head is provided which comprises a tubular wall 11 adapted to be mounted in a ,position juxtaposed to the lower end of the core 6 86 whereby it forms a continuation therewith, and a socket core member 12 having an upper horizontal flange 13 contacting with the tubular member 11, a downwardly extending skirt portion 14 for forming the inner wall of the socket, and an outwardly extending flange 15 adapted to contact with the extension 10 on the outer die 2 and to form or mold the lower end of the-socket.

To support the members 11 and 12 at the :position shown with respect to the die 2 and "the core 6, abase 16 is provided. As shown in Figure 2, this base 16 comprises a central hub member 17 and a plurality of spoke members 18 projecting radially therefrom. The member 12 upon the radially extending arms 18, and the tubular member 11 is likewise supported upon the arms 18 in a manner to be described later.

The socket core members 11 and 12 are secured in position against the inner die 6 and the outer die 10 by hooks 20 which are bolted to the outside of the die 10 as shown and which engage with the under sides of some of the arms 18. Thus, in Figure 1, oppositely extending radial arms 18 are shown supported upon the horizontally extending portions 19 of two opposite hooks 20, these hooks 20 being open on one side so that the arms 18 of the base 16 may be disengaged therefrom by rotating the former-head through a small angle.

Clay pipe presses are commonly provided with a disc rod 21 which is movable vertically independently of the operation of the pipe press itself, for supporting discs which support the pipe while it is being extruded from the press. This disc rod 21 is used also to raise a former-head into position, to pivotally support it while it is rotated into or out of engagement with the hooks 29, and to lower it out of the way after a socket is formed. Since the mechanism for operating the disc rod 21 is old, it has not been shown in the drawing.

The apparatus as so far described is substantially the same as that previously used. The novel feature of the present construction involves the making of the tubular member 11 as a separate and distinct element from the outer portion 12 of the formenhead, and providing means for moving tubular member 11 independently of the por tion 12. To this end, the tubular member 11 is provided with three slots 22, each of which is shaped as shown in Figure 3, and there is provided to engage with each slot 22, a pin 23 secured to and supported by a bracket 24. bolted to one of the arms 18, all as shown in Figure 2. It will be observed that the pins 23 engaging in slots 22 control the vertical position of the tubular member 11 and that if the member 11 is rotated it will be guided by the pins 23 to move in spiral direction upward or downward as the case may be, depending upon the direction of rotation. It will also be observed that when the member 11 is in its uppermost position, pins 23 lie in the lower ends 22a of slots 22, and these portions 22a of the slots are substantially horizontal, so that there is no possibility of the member 11 sliding downward from its upper position, by its own weight.

To control the rotational motion of the tubular member 11 with respect to the rest of the apparatus a curved rack 25 is provided on its inner lower surface. This rack engages with a pinion 26 mounted upon a shaft 27 journalled in a hole drilled through one of the arms 18. A horizontally projecting arm 28 is attached to the lower end of shaft 27 whereby the shaft may be rotated to turn the pinion 26 and thus rotate the tubular member 11 through a small arc. It will be observed from Figure 1 that the pinion 26 is sufficiently long to engage the rack 25 in all positions of the tubular member 11 as the latter moves from its uppermost position as shown in the drawing to its lowermost position in which pins 23 would be in the upper ends of slots 22.

A clay press fitted with the improved formerhead as described operates as follows:

The former-head is first placed upon the disc rod 21 and raised into position against the skirt 10 of the external die 2 and secured in position by rotating the base 16 to engage the arms 18 with the hooks 19. The handle 28 is then rotated to move the inner member 11 into its uppermost position, in which it is in contact with the lower end of the core 6, and clay under pressure is then admitted down through the cylinder 1 and the restricted portion '7 of the external die '2 into the space provided between the skirt 10,

the tubular member 11, and the socket core member 12 of the former-head. The clay fills the space described, forcing out the air that was in the mold through various air holes 29 in the external die and in the horizontally extending flanges 13 and 15 of the member 12. The operator is enabled to tell when the mold is filled by the extrusion of the clay from these air holes.

When the clay socket is formed as described the admission of the clay is stopped and the former-head removed in the following steps:

First, the handle 28 is revolved to turn shaft 27 and pinion 26 in such a direction as to rotate the tubular member 11 in its downward spiral path until the upper end of this member is withdrawn substantially flush with the top of the flange 13 of the member 12. During this movement of member 11 it will be observed that no portions of the clay in contact therewith can tear away from the remainder of the clay mass for the reason that it is supported by the still stationary flange 13 of the former-head. Second, the base 16 is rotated upon the disc rod 21 to disengage arms 18 from the retaining hooks 20, which action simultaneously shears the portion 12 of the former-head loose from the clay socket. Third, the entire former-head is lowered away from the die upon the disc stem 21, and removed. Thereafter, a pipe supporting disc may be placed upon the disc rod 21 and the latter run up into position to support the newly formed clay socket, as the pipe of which it forms a portion is extruded.

The above described method of removing the former-head from contact with the newly formed clay socket in two separate sections clearly reduces the danger of rupturing the clay because the portion 12 of the former-head supports the clay while the tubular portion 11 is removed, and the area of the remaining portion of the form is substantially less than it would be if the former were made in one piece. The two-piece construction further facilitates removal since the removal of the portion 11 breaks the vacuum that normally exists between the former-head and the clay socket.

Still another advantage of the present construction is that the member 11 and the core 6 may be so proportioned as to bring the line of contact between these members substantially above the restricted portion '7 of the outer die. This is advantageous because, due to the impossibility of making a perfect seal between tubular member 11 and core 6, there is always a small ridge of clay formed at the juncture of these two members and it is advantageous to have this ridge positioned some distance within the shoulder of the socket on the finished pipe. In using the ordinary type of former-head, it is necessary, in order to facilitate the removal of the former-head prior to extrusion of the pipe barrel, to extend the finishing surface of the core below the corresponding finishing surface of the die, thus bringing the line of joinder between the core and the tubular member of the former-head substantially at the inner end of the socket.

Furthermore, it is sometimes advantageous to vary the vertical position of the line of contact between the core member 6 and the tubular member 11 in manufacturing pipe of different sizes and in using diiferent clays. My improved former-head affords maximum flexibility in this respect and closer control of the extrusion process so as to obtain the best product.

I claim:

1. Apparatus for pressing socket-end clay pipe comprising a pipe die and socket mold, a pipe core, means for supplying clay under pressure between said pipe die and pipe core, a former head removably securable in position with respect to said socket mold, said former-head comprising a skirt member cooperating with said socket mold to shape the socket on a pipe, and a tubular member for shaping the inner surface of the pipe adjacent its socket end, said tubular member being movable in telescopic relation with said skirt member from a position extending above said skirt member in which its upper end is against the lower end of said pipe core to a lower position in which its upper end is spaced below said pipe core, and means for moving said tubular member independently of said skirt member.

2. A former-head for use on a clay-pipe press comprising a unitary pipe die and socket mold and a pipe core within the pipe die; said formerhead consisting of apparatus attachable and removable as a unit from the press and comprising a skirt member for forming the inner surface of the socket on a pipe, a tubular member of the same diameter as and shaped to fit against the lower end of the core of the pipe press with which the former-head is to be used, for forming the inner surface of that portion of a pipe contiguous to the socket thereon, means for supporting said skirt member against the socket mold of said press, means for movably supporting said tubular member with respect to said skirt member, and means for moving said tubular member with respect to said skirt member into and out of contact with the lower edge of the pipe core of the press, the pipe core and tubular member forming a substantially continuous cylindrical surface when in contact.

3. A former-head as described in claim 2 in which said tubular member is movably supported with respect to said skirt member in telescopic relation therewith.

4. A former-head as described in claim 2 in which said tubular member is movably supported with respect to said skirt member for movement in a spiral path telescopically within said skirt member.

5. A former-head for use on a clay-pipe press comprising a unitary pipe die and socket mold and a pipe core within the pipe die; said formerhead consisting of apparatus attachable and removable as a unit from the press and comprising a skirt member for forming the inner surface of a socket on a pipe, a tubular member for forming the inner surface of the pipe contiguous to said socket, means for rigidly securing said skirt member to the socket mold of said press, means for movably supporting said tubular member with respect to said skirt member, and means for moving said tubular member with respect to said skirt member into and out of contact with the lower edge of the pipe core of the press, the pipe core and tubular member forming a substantially continuous cylindrical surface when in contact.

WILLIAM McCLINTOCK. 

